fix(Transformers): do not transform Date objects (#8463)

packages/discord.js/src/util/Transformers.js

@@ -9,6 +9,7 @@ const snakeCase = require('lodash.snakecase');
  */
 function toSnakeCase(obj) {
   if (typeof obj !== 'object' || !obj) return obj;
+  if (obj instanceof Date) return obj;
   if (Array.isArray(obj)) return obj.map(toSnakeCase);
   return Object.fromEntries(Object.entries(obj).map(([key, value]) => [snakeCase(key), toSnakeCase(value)]));
 }